Replace httr with httr2

Change-Id: I196d7eed6560a560a74d31cdaba8715c89e4b4cf
diff --git a/man/KorAPConnection-class.Rd b/man/KorAPConnection-class.Rd
index 363f97b..4c75799 100644
--- a/man/KorAPConnection-class.Rd
+++ b/man/KorAPConnection-class.Rd
@@ -92,7 +92,7 @@
 
 \item{url}{request url}
 
-\item{json}{logical that determines if json result is expected}
+\item{json}{logical that determines if JSON result is expected}
 
 \item{getHeaders}{logical that determines if headers and content should be returned (as a list)}